The new forums will be named Coin Return (based on the most recent
vote)! You can check on the status and timeline of the transition to the new forums
here.
The Guiding Principles and New Rules
document is now in effect.
Maybe! The mosquitoes in my area have been unbearable this year so we've had a company come out every three weeks to do a barrier spray. My wife has recently become concerned that the spray is affecting the bees in our yard, which she wants around to pollinate our three smallish gardens (on top of just wanting to be nice to bees in general). What they're spraying is listed below and we've already googled to get the basics but we figured we'd ask, do any of you know enough about bees to say whether what we've had sprayed is going to be a problem?
cykick cs (1.5 oz./gallon)
bifen it (1/3 oz./gallon)
New balance (8 oz./gallon)
0
Posts
The bug signal has been lit!
They are both pyrethroid insecticides and generally safe for humans. New Balance is basically a protective mixture added to the pesticides to prevent them from breaking down in the environment.
In terms of honeybee health, though, the data is a bit harder to suss out. Bifenthrin has been shown to have a pretty high LD50 (17mg/bee) so it's pretty safe for bees....although there have been studies that demonstrate long-term chronic effects of exposure on things like learning, bee development, and a few other things. Although, if I remember correctly, some of this research is contentious.
However, Cyfluthrin is probably pretty bad, overall. The only real reference I can find describes an LD50 of like 0.037mg/bee. That's....pretty low, thus pretty toxic. There's also some evidence that Cyfluthrin also impairs learning and development, but it's less well studied than Bifenthrin.
Here's the thing though, a lot of this stuff is not very persistent in the environment (hence why they mix it with New Balance). Unless it's being sprayed directly onto a bee, they probably won't die.
That being said, let me just put it this way
If someone is spraying pesticides into your yard, you are going to kill bees. That's just how it goes.
Overall, though, unless you have massive properties and are spraying when bees are actively flying around, you probably wont contribute too much to overall bee death. You can maybe politely ask the company to avoid spraying on your gardens, to avoid bees picking up residue during pollination (and to preserve other beneficial insects in the garden!)
Remember that unless you have active hives in your yard also, the bees aren't living there.....on the other hand, you're probably killing a ton of native bees, many of whom are actually better pollinators than honeybees.
Out of curiosity, where do you live?
Overspraying for mosquitoes is definitely a problem for bee health, although in this case I'd take the tons of dead commercial honeybees over having Zika spread to my home state.
This seemed relevant:
I wouldn't bother with alternative sprays, honestly. They suck, and don't usually work, and ironically a lot of the other pesticides (pyrethroids....) are derived from the active compounds in the natural sprays....
Though now I'm wondering what the basis of selectivity for pyrethroids in general is...
It's complicated and not well understood. Different isomers of the molecules have vastly different selectivity against both insects and vertebrates. For instance, Casida et al, 1983 note that
They also go on to note the following
Finally, they also note that in many cases, the low mammalian toxicity of some pyrethroids is also due to to low never sensitivity to these chemicals (pyrethroids , for context, are nerve agents....as are most pesticides)
If you're wondering about in an evolutionary context, the short answer is that pyrethroids evolved as part of plant secondary metabolic defenses against insect herbivory more than mammalian herbivory, and thus there wasn't selective pressure to evolve something that was effective as broadly in this group of plants.
Anyway, this is what they have to say, with more up-to-date information about pyrethroid selectivity.
So, there you go @VishNub
If I ever need a variable to define a preference for eating vegetation, or a thematic homonym thereof: You just named it.
I'll take the praise but this is a word that's been coined years ago, I hardly came up with it, I'm not that clever.
Could you just use mosquito repellent maybe?
We took three with us camping and made a little perimeter around the campfire and they kept the mosquitoes away the whole time there as well.
These things. Buy a few and set up a perimeter of where you're hanging out.